The solution from J. A. Calvo
wget http://archive.ubuntu.com/ubuntu/pool/main/a/apt/libapt-pkg5.0_1.2.29_amd64.deb
sudo dpkg --install --force-downgrade libapt-pkg5.0_1.2.29_amd64.deb
Did not work for me, I got a 404 error.
Mrme's solution worked though and I am now up and running. Thank you!
wget https://launchpad.net/ubuntu/+archive/primary/+files/libapt-pkg5.0_1.2.29_amd64.deb
sudo dpkg --install --force-downgrade libapt-pkg5.0_1.2.29_amd64.deb